Merge branch 'ping6-SOL_IPV6'

Jakub Kicinski says:

====================
net: ping6: support setting basic SOL_IPV6 options via cmsg

Support for IPV6_HOPLIMIT, IPV6_TCLASS, IPV6_DONTFRAG on ICMPv6
sockets and associated tests. I have no immediate plans to
implement IPV6_FLOWINFO and all the extension header stuff.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/ip6_output.c

@@ -1487,6 +1487,7 @@ static int __ip6_append_data(struct sock *sk,
 
 	if (cork->length + length > mtu - headersize && ipc6->dontfrag &&
 	    (sk->sk_protocol == IPPROTO_UDP ||
+	     sk->sk_protocol == IPPROTO_ICMPV6 ||
 	     sk->sk_protocol == IPPROTO_RAW)) {
 		ipv6_local_rxpmtu(sk, fl6, mtu - headersize +
 				sizeof(struct ipv6hdr));

net/ipv6/ping.c

@@ -101,11 +101,21 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 	ipc6.sockc.tsflags = sk->sk_tsflags;
 	ipc6.sockc.mark = sk->sk_mark;
 
-	err = sock_cmsg_send(sk, msg, &ipc6.sockc);
-	if (err)
-		return err;
+	if (msg->msg_controllen) {
+		struct ipv6_txoptions opt = {};
+
+		opt.tot_len = sizeof(opt);
+		ipc6.opt = &opt;
 
-	/* TODO: use ip6_datagram_send_ctl to get options from cmsg */
+		err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6);
+		if (err < 0)
+			return err;
+
+		/* Changes to txoptions and flow info are not implemented, yet.
+		 * Drop the options, fl6 is wiped below.
+		 */
+		ipc6.opt = NULL;
+	}
 
 	memset(&fl6, 0, sizeof(fl6));
 
@@ -140,7 +150,8 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 	pfh.wcheck = 0;
 	pfh.family = AF_INET6;
 
-	ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
+	if (ipc6.hlimit < 0)
+		ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst);
 
 	lock_sock(sk);
 	err = ip6_append_data(sk, ping_getfrag, &pfh, len,

tools/testing/selftests/net/cmsg_ipv6.sh

@@ -0,0 +1,156 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+ksft_skip=4
+
+NS=ns
+IP6=2001:db8:1::1/64
+TGT6=2001:db8:1::2
+TMPF=`mktemp`
+
+cleanup()
+{
+    rm -f $TMPF
+    ip netns del $NS
+}
+
+trap cleanup EXIT
+
+NSEXE="ip netns exec $NS"
+
+tcpdump -h | grep immediate-mode >> /dev/null
+if [ $? -ne 0 ]; then
+    echo "SKIP - tcpdump with --immediate-mode option required"
+    exit $ksft_skip
+fi
+
+# Namespaces
+ip netns add $NS
+
+$NSEXE sysctl -w net.ipv4.ping_group_range='0 2147483647' > /dev/null
+
+# Connectivity
+ip -netns $NS link add type dummy
+ip -netns $NS link set dev dummy0 up
+ip -netns $NS addr add $IP6 dev dummy0
+
+# Test
+BAD=0
+TOTAL=0
+
+check_result() {
+    ((TOTAL++))
+    if [ $1 -ne $2 ]; then
+	echo "  Case $3 returned $1, expected $2"
+	((BAD++))
+    fi
+}
+
+# IPV6_DONTFRAG
+for ovr in setsock cmsg both diff; do
+    for df in 0 1; do
+	for p in u i r; do
+	    [ $p == "u" ] && prot=UDP
+	    [ $p == "i" ] && prot=ICMP
+	    [ $p == "r" ] && prot=RAW
+
+	    [ $ovr == "setsock" ] && m="-F $df"
+	    [ $ovr == "cmsg" ]    && m="-f $df"
+	    [ $ovr == "both" ]    && m="-F $df -f $df"
+	    [ $ovr == "diff" ]    && m="-F $((1 - df)) -f $df"
+
+	    $NSEXE ./cmsg_sender -s -S 2000 -6 -p $p $m $TGT6 1234
+	    check_result $? $df "DONTFRAG $prot $ovr"
+	done
+    done
+done
+
+# IPV6_TCLASS
+TOS=0x10
+TOS2=0x20
+
+ip -6 -netns $NS rule add tos $TOS lookup 300
+ip -6 -netns $NS route add table 300 prohibit any
+
+for ovr in setsock cmsg both diff; do
+    for p in u i r; do
+	[ $p == "u" ] && prot=UDP
+	[ $p == "i" ] && prot=ICMP
+	[ $p == "r" ] && prot=RAW
+
+	[ $ovr == "setsock" ] && m="-C"
+	[ $ovr == "cmsg" ]    && m="-c"
+	[ $ovr == "both" ]    && m="-C $((TOS2)) -c"
+	[ $ovr == "diff" ]    && m="-C $((TOS )) -c"
+
+	$NSEXE nohup tcpdump --immediate-mode -p -ni dummy0 -w $TMPF -c 4 2> /dev/null &
+	BG=$!
+	sleep 0.05
+
+	$NSEXE ./cmsg_sender -6 -p $p $m $((TOS2)) $TGT6 1234
+	check_result $? 0 "TCLASS $prot $ovr - pass"
+
+	while [ -d /proc/$BG ]; do
+	    $NSEXE ./cmsg_sender -6 -p u $TGT6 1234
+	done
+
+	tcpdump -r $TMPF -v 2>&1 | grep "class $TOS2" >> /dev/null
+	check_result $? 0 "TCLASS $prot $ovr - packet data"
+	rm $TMPF
+
+	[ $ovr == "both" ]    && m="-C $((TOS )) -c"
+	[ $ovr == "diff" ]    && m="-C $((TOS2)) -c"
+
+	$NSEXE ./cmsg_sender -6 -p $p $m $((TOS)) -s $TGT6 1234
+	check_result $? 1 "TCLASS $prot $ovr - rejection"
+    done
+done
+
+# IPV6_HOPLIMIT
+LIM=4
+
+for ovr in setsock cmsg both diff; do
+    for p in u i r; do
+	[ $p == "u" ] && prot=UDP
+	[ $p == "i" ] && prot=ICMP
+	[ $p == "r" ] && prot=RAW
+
+	[ $ovr == "setsock" ] && m="-L"
+	[ $ovr == "cmsg" ]    && m="-l"
+	[ $ovr == "both" ]    && m="-L $LIM -l"
+	[ $ovr == "diff" ]    && m="-L $((LIM + 1)) -l"
+
+	$NSEXE nohup tcpdump --immediate-mode -p -ni dummy0 -w $TMPF -c 4 2> /dev/null &
+	BG=$!
+	sleep 0.05
+
+	$NSEXE ./cmsg_sender -6 -p $p $m $LIM $TGT6 1234
+	check_result $? 0 "HOPLIMIT $prot $ovr - pass"
+
+	while [ -d /proc/$BG ]; do
+	    $NSEXE ./cmsg_sender -6 -p u $TGT6 1234
+	done
+
+	tcpdump -r $TMPF -v 2>&1 | grep "hlim $LIM[^0-9]" >> /dev/null
+	check_result $? 0 "HOPLIMIT $prot $ovr - packet data"
+	rm $TMPF
+    done
+done
+
+# IPV6 exthdr
+for p in u i r; do
+    # Very basic "does it crash" test
+    for h in h d r; do
+	$NSEXE ./cmsg_sender -p $p -6 -H $h $TGT6 1234
+	check_result $? 0 "ExtHdr $prot $ovr - pass"
+    done
+done
+
+# Summary
+if [ $BAD -ne 0 ]; then
+    echo "FAIL - $BAD/$TOTAL cases failed"
+    exit 1
+else
+    echo "OK"
+    exit 0
+fi